The present invention relates to the field of paper manufacturing. More particularly, the present invention relates to the manufacture of absorbent tissue products such as bath tissue, facial tissue, napkins, towels, wipers, cardboard, and the like. Specifically, the present invention relates to improved papermaking fabrics used to manufacture absorbent tissue products, methods of tissue manufacture, methods of fabric manufacture, and the actual tissue products produced thereby.
In the manufacture of tissue products, particularly absorbent tissue products, papermaking fibers are deposited onto forming wires and transferred as a newly-formed web to a transfer fabric, often with the aid of a vacuum box. From the transfer fabric, the web is then transferred to a through-air drying fabric to dry the web, which can provide the physical properties and the final product appearance to the web. There is a continuing need to improve web properties and machine operation by improving the transfer fabric. As an example, there is a need to improve the uniformity of the cross-direction (CD) strain in such transfer fabrics. There is also a need to improve through-air drying fabrics for improved operation of the machine as well as improved properties of the web and its visual appearance.
Some woven papermaking fabrics attempt to address some of these opportunities. For example, in traditional woven papermaking fabrics, topography in a transfer papermaking fabric was achieved by juxtaposing areas of tight weave of shute and warp filaments with areas of loose weave of shute and warp filaments that created unbalanced forces in the woven fabric to push long floats out of plane creating tight bundles of warp filaments. While this can provide varied topographies in the woven papermaking fabric, this technique provides some disadvantages, including, but not limited to: poor air permeability through the stacked warp filament bundles, limits on height of the topographical elements created by the warp filament bundles based on the number of warps that could be stacked (alternatively viewed as limits on pocket depth between topographical elements), difficulties in achieving uniformity of fiber support, aesthetic limitations, areas of excessive localized strain, creation of excessive pinholes especially in high cross-directional strain sheet contacting surfaces, and difficulties in weaving designs. Some of these disadvantages due to past woven papermaking fabric techniques can lead to deficiencies in the tissue being carried and produced on the papermaking fabric. For example, warp filament stacking can create areas of low basis weight in the base tissue sheet, decreased drying efficiency, and difficulties in tissue sheet release.
As such, there remains a need for articles of manufacture and methods of producing tissue products with improved physical properties without losses to tissue machine efficiency and productivity.